1. Field
The following description relates to a cognitive radio communication system. More particularly, the description relates to a cognitive radio communication terminal and method of transmission.
2. Description of Related Art
Much research is currently underway involving technologies that efficiently use limited frequency resources. Cognitive radio (“CR”) technology is in the spotlight.
Currently, use of unlicensed devices such as a wireless local area network (“WLAN”), Bluetooth, and the like is increasing. The number of frequency bands and system standards that such unlicensed devices may is are also increasing.
Instead of a centralized cellular communication that may centrally manage and use radio resources, the unlicensed device may adopt a distributed communication protocol where terminals access radio resources to perform communication.
The distributed communication protocol may be easily embodied and have less complexity. However, as the number of terminals in a network increases, a potential collision between the terminals may become serious and thereby deteriorate transmission efficiency. Accordingly, there is a need for a new technology that may adapt to a varying amount of unlicensed devices in a network and enable the unlicensed devices to effectively communicate.